Expected output:

With N=4 (2 search qubits) and M=1 (one marked item |11⟩),
the Grover operator has eigenvalues e^(±2iθ) where sin²(θ) = M/N = 1/4,
so θ = π/6.

The phase φ = θ/π = 1/6 ≈ 0.1667.
With 2 counting qubits (resolution 1/4), the nearest value is
either 0/4 = 0 or 1/4 = 0.25.

Expected output (1024 shots, approximate):
{'01': ~750, '00': ~274}

The dominant outcome '01' (decimal 1) gives φ ≈ 1/4 = 0.25,
which corresponds to sin²(π × 0.25) = sin²(π/4) = 0.5.
Estimate: M ≈ 0.5 × 4 = 2.

The true answer is M = 1. With only 2 counting qubits, the precision
is limited. More counting qubits give better estimates.

With 3 counting qubits, you'd get φ ≈ 1/8 or 2/8,
giving M ≈ 0.59 or M ≈ 2 — rounding to M = 1. ✓